Ozone (O3), that is an isotope of oxygen, is known to have strong sterilizing power, deodorizing power, oxidizing power, and bleaching power. Technology that uses ozone gas for sterilization and deodorization of inside refrigerators has been developed in recent years by taking advantage of these characteristics (see, for example, Patent Literature 1). Ozone water containing ozone dissolved therein is used in sterilizing devices placed at factories or hospitals, in cleaning devices of semiconductor wafers, and others.
Ozone is generated by various known techniques, of which the most widely applied one employs corona discharge or silent discharge. An ozone generator employing such a discharge technique is used in the refrigerator disclosed in Patent Literature 1. When ozone water is used, the following way is generally employed in which ozone gas generated by an ozone generator such as that described above is dissolved in water by bubbling or ejection technique, thereby generating ozone water.
By way of example, the device disclosed in Patent Literature 2 includes a circulation filtering unit for bathwater that uses ozone. In this device, ozone gas generated by an ozone generator and bathwater are stirred in a pump, so that ozone is dissolved more quickly in the bathwater.
However, the ozone generator employing a discharge technique has problems such as instability of the amount of generated ozone under the influence of humidity and the like, and generation of an undesirable by-product such as nitrogen oxides. The technique of generating ozone water by dissolving ozone gas in water is likely to increase the scale of a device. Accordingly, this technique is hard to apply in home appliances in respects of size and cost.
In addition, ozone affects adverse effects on human bodies. Accordingly, except for special usages in factories or hospitals, for example, it has been difficult to take advantage of its strong sterilizing power and deodorizing power mentioned above.
In light of the problems described above, the following air conditioner (Patent Literature 3), floor-standing air disinfection device (Patent Literature 4), electric device (Patent Literature 5), and others have been suggested. The aforementioned air conditioner is provided with an ozone water generator to avoid generation of slime in a drain pan. The aforementioned floor-standing air disinfection device removes a harmful substance by making gas-liquid contact between ozone water generated by an ozone water generator and external air. In the aforementioned electric device, humidity, temperature and the like are controlled by air intake. Ozone water generated by ozone water generating means is made finer or vaporized, and is then discharged into the air, thereby removing and exhausting a harmful substance.